1. Field of the Invention
This invention relates to durable-press fabrics. More specifically, it relates to a catalyst system that is useful in the treatment of cellulose-containing textile materials with certain formaldehyde-amide adduct finishing agents to give valuable durable-press properties in the textile product
2. Description of the Prior Art
Synergistic catalyst effects are produced when aluminum chlorhydroxide, hereinafter referred to as Al.sub.2 (OH).sub.5 Cl, is used with certain salts or with certain acids. Stronger catalysis results from the use of a combination of such salts or acids and Al.sub.2 (OH).sub.5 Cl than from the use of either component alone. Reinhardt et al., U.S. Pat. No. 3,909,861, have amply demonstrated the uses of Al.sub.2 (OH).sub.5 Cl with various salts and acids. They have also pointed out that some known latent acidic catalysts, such as Mg(H.sub.2 PO.sub.4).sub.2, and alkaline salts are ineffective in combination with Al.sub.2 (OH).sub.5 Cl. These workers demonstrated a buffering effect with strong acids and an activating effect with weak acids by use of Al.sub.2 (OH).sub.5 Cl. They also demonstrated the effectiveness of Al.sub.2 (OH).sub.5 Cl alone as catalyst in treatments by the conventional pad-dry-cure process at temperatures of 140.degree. to 180.degree. C.
Reinhardt et al., American Dyestuff Reporter 64 (May 1975), discuss Al.sub.2 (OH).sub.5 Cl catalyst systems in the specialized techniques of moist curing and steam curing and show effective curing temperatures of from 100.degree. to 180.degree. C. In pad-dry-cure finishing, Al.sub.2 (OH).sub.5 Cl compares favorably with MgCl.sub.2, ZnCl.sub.2, and Zn(NO.sub.3).sub.2 as a catalyst. These workers, in general, teach away from curing at highly elevated temperatures when mixed catalyst systems containing Al.sub.2 (OH).sub.5 Cl are used.
Very little information is available in the literature concerning H.sub.2 O.sub.2 as a catalyst for the reaction of finishing agents used in treatment of cellulose-containing textiles to obtain wash-wear, wrinkle resistance or durable-press properties. Gagliardi, American Dyestuff Reporter 40 (November 1951) lists H.sub.2 O.sub.2 as one of five types of catalyst for resin finishing of fabric. He suggests that, in aqueous solutions containing free formaldehyde, H.sub.2 O.sub.2 will oxidize the formaldehyde to formic acid which then catalyzes the reaction of the resin with cloth. Gagliardi states that this catalyst has not been exploited commercially; the delayed formation of formic acid from free formaldehyde is one major factor hindering such exploitation. Although Gagliardi mentions H.sub.2 O.sub.2 as a catalyst no data or treatment details are presented. Apparently, very specialized conditions must be employed to obtain effective catalysis.
British Pat. No. 482,254 discloses H.sub.2 O.sub.2 as a catalyst for the condensation product of urea and formaldehyde. Of particular note in the teachings of this patent is the highly restrictive method required to make the process operative. Once fabric has been impregnated with H.sub.2 O.sub.2 and a water-soluble condensation product obtained from formaldehyde and urea, or similar amines or amides, it is necessary to quickly heat the wet, impregnated textile to the critical temperature range of 95.degree.-100.degree. C. This highly selective step is required to achieve further resin condensation in the cloth material.
In all prior work, no catalyst system has been employed that is composed of Al.sub.2 (OH).sub.5 Cl and an oxidizing agent such as H.sub.2 O.sub.2. Those systems with Al.sub.2 (OH).sub.5 Cl and another component all teach away from the conventional curing temperatures employed in the pad-dry-cure process. One skilled in the teachings of the prior art would not anticipate effectiveness of H.sub.2 O.sub.2 as a catalyst in textile finishing unless conversion of free formaldehyde to formic acid is promoted either in the treatment bath or in the impregnated fabric.